Air cleaners that use ionizing collectors effectively and efficiently remove dust, allergens and other particulates while they generally require no filter replacement. One commercially available ionizing air cleaner unit is the Friedrich model C-90A that includes a vertically removable electrostatic precipitator cartridge in a top loading tower shaped housing. A single fan moves air horizontally through the unit. The removable electrostatic cartridge contains parallel, generally flat collector electrodes, and emitter electrodes sandwiched between generally flat ionizer, divider bar electrodes of uniform, linear profile. Removal of the cartridge through the top loading housing allows cleaning the collector, emitter and ionizer bar electrodes removed therewith. Gravity assists the return of the cartridge to the housing after cleaning. The electrostatic precipitator cartridge is comparatively bulky, difficult to manipulate and hard to clean, requiring the use of a special cleaning solution each time it is a periodically cleaned.
United States patent application publication US 2005/0183576 A1 to Taylor et al., published on Aug. 25, 2005, discloses electro-kinetic air transporter conditioner devices each having first and second emitter and collector ionizing electrode arrays and a tower housing. The electrokinetic first and second emitter and collector electrode arrays create ions that both move the air axially between the first and second collector electrode arrays and condition the air, by cleaning the same as particulates are electrostatically attracted to the second collector electrode arrays and by adding ozone. In hybrid embodiments, one or more fans that may be vertically arrayed on the tower housing provide airflow that augments the airflow imparted by the electrokinetic air transport of the electrokinetic emitter and collector electrode arrays. The second collector electrode arrays are removable from the top of the tower housing for cleaning, but the first emitter electrodes arrays, that are not removable from the tower housing, are cleaned in situ by the use of a tool adapted to clean the wire emitter electrodes inside the tower housings.
Other electrostatic ionizing collectors and tower shaped housings are disclosed by U.S. Pat. No. 3,495,381 issued Jun. 26, 1967 to Flanagan; U.S. Pat. No. 6,926,762 B2 issued Aug. 9, 2005 to Kim et al; and United States patent application publication US 2006/0130657 A1 to Bohlen et al. In Flanagan, four (4) vertically arranged fans move air horizontally through ionizing and precipitating components carried by a tower air filtering apparatus. Kim et al. discloses first and second fans and first and second filtering units that are vertically arrayed to a tower air cleaning apparatus. Each of the first and second filtering units includes electrostatic dust filters providing ionization of dust particles. The fans move air horizontally through the tower air cleaning apparatus. Bohlen et al. discloses multiple, vertically arrayed fans moving air horizontally through an electrostatic precipitator mounted in a tower ionizer air cleaner. The utility of these electrostatic ionizing collectors and tower shaped housings has been limited by their comparative bulk, cost, particulate removal efficiency, air cleaning capacity and/or by having been difficult or toilsome to clean.
There is thus the need to provide an electrostatic filter cartridge for a tower air cleaner providing improved cleanability and particulate collection efficiency that is comparatively inexpensive to manufacture while providing a clean air delivery rate sufficient to maintain at least an average size room free of dust, dirt, allergens and other particulates.